1. Thomas Jefferson’s purchase of the Louisiana Territory and the Lewis and Clark Expedition opened the west which led to Sectional Polarization.
2. Growth in transportation technologies, such as steam-powered locomotives, steamships, railroad tracks, and canals led to Sectional Polarization.
3. Urban growth in the north, compared to the south and west, as well as differences in the geography (climate and terrain), led to Sectional Polarization
